Sewing-machine thread pull-off.



A. E, JUHNSON. SEWING MACHINE THREAD PULLOFP. APPLIGATXON FILED JALM, 1910.` 1,982,635, Patented Dec. 30, 1913.

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A. E. JOHNSON. SEWING MACHINE ,THREAD PULL-OFF. APPLIGATI'ON FILED M1114, 1910.

1,082,636.- Patented Dec. 30,1913.

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232 26 WlDessSes: In enten 'l a/M uurrnn srarns PATENT OFFICE.

LBERT E. JOHNSON, QE BEVERLY, MASSAGHUSETTS, ASSIGNORTO' UNITED SHOE MACHINERY COMPENY, F PATERSON, N EW JERSEY, A CORPORATION OF NEW SE'tVINGddACI-IINE THREAD PULL-OFF.

aosaesei.

Specification of Letters Patent.

Patented Dec. 30, 1913.

Application filed January 1.4, 1910. Serial No. 538,086.

' chine Thread Pull-Oils; land l do hereby deetti clare the following to be full, clear, and exact description of the invention, such as will. enable others skilled in the art to which it'appertains to maire and use the. same.

rThis: invention relates to attachments l'or sewing machines designed to provide for a sufficient freeend of t-hread at the working point, after the removal of one piece of work, for use in the formation of the tirst stitch in the new worlr to be operated apen. The invention relates more particularly to an attachment for thc purpose described which instead of operating on the tension device, as is common, opcrates'dircctly on the thread to pull it through the tension. The attachment may, therefore, conveniently be termet i thread pull-oit.7

it is d l`ble, in devices of this character, that the slacli thread for use in forming the tirst stitch in new wort: be provided before remo-val of the old work from the machine so that when the old work is removed the desired length of thread may be drawn freely tln'ough the guides and eye of the needle. @ne object or the present invention, there ifo-rm' is to` insur'c the provision of slacl; thread, for use in the formation of the first stitch in new work, prior tothe removal of the Old work romthe machine.

In accordance with this object,'one feat-ure ot' the invention.comprises a mechanically operated thread pull-olip constructed and ar` ranged to operate in advance ot' the 'removal of the work which has just been completed. To insure suchy an operation of the thread pull-oli' it .may conveniently be connected to the devices for lifting the presser foot from the work so that when the presser toot is lifted slack thread will be drawn through the tension device.

It is obvious that the strain placed upon the thread by the pull-oli' should be removed prior to the removal of the old work so that no hindrance to the readyvpassage of the slaoir thread through the guides will be interposed.

Another object of the invention is'to provide a thread pull-oit which, after having performed l its work to obtain the desired amountof slack thread, 'will be actuated to remove pressure .from the bight of thread which it has formed.

In accordance with this object a further feature of the-invention consists in the con struction and arrangement of the thread pull-oit in which a thread pulling finger acts upon .the thread to draw slack through Vthe"tension device and is then automatically7 returned to its normal, operative position prior to the removal of the old work.

1n the illustrated embodiment of the invention an oscillatory thread pulling linger, having a thread engaging end, is provided at the forward side oit' the tension device and this linger is Os'cillated to pull thread through the tension device by means of' an actuator connected with the devices controlled by the operative for lifting the presser foot preparatory to 'removing the work. Means is provided for breaking the connection between the linger and its actuator after the desired length of thread has been pulledl off anda spring then returns the finger to its normal, operative position.' The thread pulling linger is thus actuated to form slack thread by means under control of the operative but is automatically returned to its normal, operative position. A variation in the length of thread pulled olf is obtained by avaria-tion in the effective length of' the oscillatory thread pulling finger.

A thread pull-oli' of the character described pro-vides for the withdrawal ci? a definite amount of thread from 'the spool, the thread pulling finger being preliminarily adjusted-by the operative thus prede` termining theamount in accordance with the length of thread necessary in stitching through any particular pieo'e of work being operated upon. By this means a Waste of thread is prevented.

Other features of the invention, comprising certain details of construction and combinations of parts, will be further explained in the following description and thenipointed out in the' appended claims' l A In the drawings, which illustrate the best form 4of the invention now known to the inventor, the thread pull-oli" has been shown as applied to the .well `known `Vtillcox & Gibbs domestic sewing machine although it should be distinctly understood that the inthread puller at-.therea-r. of the machineg. Flig. 3 -is a plan of the parts shown in Fig. 2; and Figs. 4 and 5 are detached details, in

perspective, to be referred to.

In the illust-rated embodiment of the invention the domestic or household 1iiillcox '& Gibbs sewing machine head, except for certain modifications l referred to later, -is

mounted on a base 1 and is provided with' theusual stitch forming mechanism including the eye-pointed needle 2V and rotary thread hook or cast-off 3, the latter 'being mounted at oneend ofthe driving shaft 4 rotated by a belt running over the sheave 5. lThe needle is actuated in the usual manner.

The work is fedouer the table 6 by the feed foot 7 actuated in the usual manner. The work is held upon the table 6 during the formation of the stitches by the presser foot 8 having the-usual connections. The thread 9 leads from the spool -or bobbm (not shown.) through a usual form of tension device 10, and through the ordinary guides,

to the eye of the needle.

The head .as illustrated, modified from the commercial machine to the extent that the work table is smaller, the feed foot is thinner, and an additional work supporting roll 11 is provided mounted cn a pivoted lever 12, and held in a position opposite the edge ofthe work table by a coiled spring 13. These changes are for the purpose of adapting the machine to sewing 'together the two aps of an Economy insole to form a single,

compound lip. As the changes form noY part of the present invention, being claimed 1n aco-pending application of-even date herewith Serial No. 538,0S7,-they will not be referred to further herein.

The'. presser foot 8 is provided with a shoulder 14' (dotted linesy Fig. 1) which is engaged by the left hand endof a lever'l of the first class, fulcrumed on a stud 16 in a bracket carried.- by the frame (Fig. 1). The lever 15 is. adjustably connected, b y its right hand end,l to a lever 17 of the second class, also fulcrumed on the stud 16, and is actuated by said lever 17.- A chain 18 depends from the -free end of the lever 17 and has connected thereto a treadle of' usual form (not shown). Y

Rising from` the lever 17 and, pivotally mounted thereon by its lower end is an arm or actuator 1 9 having a hooked end 20. A leaf spring 21 'mounted on a bracket 22,

' which embraces the arm 19 and acts as a guide therefor, holds'said arm'in Contact with a rotary cam-shaped member 23 (-Fig.

4) pinned to one end of a. rocky. shaft 24 journaled in the upper portion of the frame. The rotary member 23 is prorided with a slabbed-off side 25 ending in a hook or spur 2G and, substantially diamctrically opposite the spur, with a shoulder '27. The rotarymember 23 is normally maintained with its shoulder 27 in engagement with a stop screw 28 by means of/a suitably connected coiled spring 29 (Fig. 3) surrounding the shaft 24. The `end of the shaft 24, opposite 'to that on which the member 23 is mounted, is split (Fig. 1) and drilled dia- -metrically for the reception ofthe shank of a thread pulling finger. 30 which is clamped in place by tightening a. screw 31 in the shaft'. The finger 30 extends forward 'and is provided at its free end with an eyev 32 (Fig. 5) adjacent the tension device through which the thread freely passes after it leaves the tension. The-. coiled spring 29 maintains the finger 30 normally in its operative position as shown indium 1.

In the operation of the macii'me, after the stitching on any'V particular pifece of work has been completed, the free endlof the lever 17 isdrawn downby operating the treadle attached to the chain 18 and the presser foot 8 is thuslifted from the work by the engageme'nt of the upwardly moving end of the lever 15 with the presser foot shoulder 14. The downward movement of the' lever 17 carries down with it the arm 19 causing its hooked 'end 20 toengage the spur 26 on the rotary member 23 and rock the shaft 24. The, rocking of lthe shaft 24 continues until the upper end of the slabbed off portion 25 of the rotary member engages the h ook 2O (see dotted lines Fig. 2) and, acting as a tap'pet cam, pushes the hook off of the spur. The' rocking of the shaft 24 has, however, brought the thread pulling finger to" 'the 'lower dotted line position of Fig. 2 pulling. thread through the tension-and forming a bight of the desired size in the thread,- as shown in dotted lines. Immediately the arm 19' is disengaged 'from.the rotary member 23 the coiled spring 29 acts to rock the shaft 24 backward and bring the finger 30vto its normal, operative position vthus relieving thc thread of pressure rfrcnrthe finger. Viith this construction the finger is automatically returned to its initial position' :while the presser foot is. held lifted and by means independent of the means for operating it. Viththe finger in its initial position andthe presser foot still held lifted, the work may be removed and the slack thread readily drawntaut through the finger, guides and eye of the needle. At the time the thread is severed the free end of thread thus obtained ha's been drawn through the eye of the needle to apo-sition ready for use in the forma-tion 'of the first stitch in the new work. The amount-of thread pulled from the' spool and thesize of the bight formed by ioo device, a presser foot, means to`lift the" presser foot, a thread pulling linger, Aoperative 'connections from the presser foot lifting means to move the ingei` in adirection to pull thread through the `tension device, and a device for returning the finger to its initial position acting independently' of the movement-of the presser lfoot lifting means.

2. A sewing machine, having, in combina-- tion, stitch forming mechanism, al tension device, a thread pulling finger, a 'presser foot, 'means to lift the presser Jfoot and actuate the finger to pull thread through the tension device, and means to return the finger to its normal, operative position While the presser `foot, isheld lift'ed.

3. A sewing machine having, in combina-l tion, stitch forming mechanism,l a tension' device, a rock shaft havinga thread-engaging member mounted thereon, a cam member mounted upon saidshaft, an arm in operative engagement' With said cam member, means to actuate the arm and move the rockshaft to cause the thread-engaging tion, 'stitch orming` mechanism, a'. tension device, a rock shaft having a lthread engaging nger, a cam member having a spur mounted on said shaft, a. hookedarm for engaging said spur, means to actuate'the arm to ro'ck the shaft and cause the finger to pull slack thread through the tensionl device, a shoulder on the cam member tofengage the hooked arm during the rocking of the shaft and disengage it from the 'spur and means to return the shaft and finger to'their initial positions.

5. A sewing machine having, in combination, stitch forming mechanism, a tension device, a rock shaft having a thread-engaging finger, a rotary cam memberhaving a spur mounted'on said shaft, a hooked arm 'for engaging said spur, means to actuate .the arm to rock the shaftand cause the finger to pull slack thread through the tension device,

a. slabbed-oif'po'rtion terminating in a shoulder formed on the cam member to engage the hooked arm during the rocking of the shaft and disengage it from 'the spur, 'and mea-ns' to return the shaft and finger to their initial position. i

A ALBERT E. JOHNSON. Witnesses:

RUTH A. SiMoNns, WARREN G. OGDEN. 

